EDTA as an anticoagulant - (Nov/19/2009 )

I need to use 20mM EDTA as an anti-coagulant during blood collection where the blood will be used for haemagglutination assays so I need to collect erythrocytes. The protocol calls for 1ml of 20mM EDTA per 5-10ml of blood but is it as simple as dissolving the relevant amount of EDTA in distilled water and filtering or should it be in a buffered solution like PBS? We don't have time to wait for blood collection tubes to arrive.

Thanks

-floyd78-

Hello Floyd,

We regularly use 0.5 M EDTA in water, 1 ml:10 ml whole blood. (Yes, this is overkill.) You can dissolve the EDTA in water or PBS, but sometimes the PBS will precipitate out when you adjust the pH too high. (EDTA won't go into solution until ~8.0).